PHILRICE NEGROS
TABLE OF CONTENTS
Executive Summary PhilRice Negros
1
Abbreviations and acronymns 18
List of Tables 20
List of Figures 21
PhilRice Negros
Branch Manager: EM Libetario Executive Summary
PhilRice Negros Branch Station based at Cansilayan, Murcia, Negros Occidental is tasked to cater to the need, and serve as distribution center, for quality seeds of high-yielding and disease-resistant modern varieties suited for the Visayas regions. The station is also mandated to develop specialty and premium rices, and develop and promote science-based organic rice farming technologies and practices.
In 2013, the research division of the station had generated
information related to selection and identification of early genotypes ideal for low-fertilization rate for drought-escape for rainfed lowland condition. Initial copies of soil series guidebooks were also produced for Negros Occidental, Negros Oriental and Bohol. In addition, three (3) profiles of pest injuries due to diseases (1), insect pests (1) and weeds (1) that commonly occurred in rice varieties planted in the station were also identified. In terms of publication, researchers of the station had submitted 10 scientific papers in various ISI journals of the country. Three of these had been accepted already since July last year. To further enhance exchange of ideas and establish collaborations, researchers with MS Degrees conducted series of seminars related to the science and technologies about rice production. During the 26th National Rice R&D Conference held on September 4-5, 2013 at PhilRice Central Experiment Station, Maligaya, Science City of Muñoz, Nueva Ecija, two (2) scientific posters of the station won first places for the best paper awards in separate themes of categories. Furthermore, the research division of the station had sourced out research grants from different DA-Regional Field Units.
The development division of the station, on the other hand, had successfully participated in the launching and in the campaign of NYR 2013 in various major events of the Visayas Regions. Two planting seasons of related to Palayabangan 10-5 Challenge in which different individuals and groups participated as contestants, as well as initial activities related to Palayamanan Plus like rice-fish culture and diversified cropping system also had been successfully implemented at the station. Part of the activity of the Palayamanan Plus was the training of selected PhilRice Staff for effective and efficient mushroom and vermicast productions. Lastly, a farmer’s field day with a theme of “Rice Festival” was successfully conducted showcasing the different rice delicacies, new inbred and hybrid rice varieties, SxP Hybrid Rice Production, Palayabangan 10-5 Challenge and Palayamanan Model.
More than 500 farmers attended the said activity.
Plant health assessment at PhilRice Negros seed production area CA Endino, DKM Donayre, and IMG Ciocon
Rice varieties planted at PhilRice Negros Seed Production Area were assessed for various pest constraints since CY 2011. The assessment was done using the IRRI survey portfolio. The survey was aimed at generating trends on pest prevalence, profile injuries due to diseases, animal pest and weeds while at the same time contributing to the development of pest management strategies in relation to production of high quality seeds.
Highlights:
Nutrient management
• Generally, nutrients were applied at the rate of 73-47-74-60kg NPKS/ha using inorganic fertilizer. Basal application was done at 10DAT with a rate of 52-47-44-36 kg NPKS/ha using 2bags 14-14-14, 1 bag 16-20-0, 1 bag 0-0-60, 1bag 18-46-0 and 2 bags 21-0-0.
• Additional N based on leaf color chart (LCC) reading was added using 2 bags 21-0-0 per ha and K2O supplemented using 1 bag 0-0-60 applied at 5 days before panicle initiation.
• Moreover, 30 bags processed chicken manure were applied to areas where low yields were previously recorded. These implied that enough nutrients were provided.
Water management
• During the wet seasons, there were no water stress observed at any crop reproductive stage.
• Insufficient water supply occurred most of the time during dry seasons and contributed to heavy weed infestations.
Crop status
• General crop status at booting stage was rated good.
• Varieties that greatly were affected by tungro during wet seasons and highly infested with weeds during dry seasons were rated poor to very poor.
Profile of injuries due to diseases
• Tungro was the common viral disease in rice seed production areas. Diseases observed that were caused by bacteria were bacterial leaf blight (BLB) and bacterial leaf streak (BLS) while leaf blast (LB), narrow brown spot (NBS), brown spot (BS) and
leaf scald (LS) for fungal diseases on leaves.
• Fungal diseases observed infecting tillers and panicles, on the other hand, were sheath blight (ShB), sheath rot (ShR), collar blast (CB), neck blast (NB), and false smut (FSm).
• Panicle blight and grain discolorations caused by complex infection of bacterial and fungal pathogens were also noted.
• Diseases were present both in wet and dry seasons but percent incidence was higher during dry seasons (Figure 1).
• Tungro was the major disease that contributed to low yield in seed production areas (Figures 1 to 6).
• Rice varieties susceptible to tungro were NSIC Rc220, NSIC Rc160, NSIC Rc146, PSB Rc14, PSB Rc82, NSIC Rc218, NSIC Rc240, NSIC Rc192, NSIC Rc288, NSIC Rc294, NSIC Rc292, PSB Rc10 and NSIC Rc170. Most of the saline prone developed varieties were susceptible to tungro.
• Varieties that were resistant to tungro were NSIC Rc120, NSIC Rc158, NSIC Rc222, NSIC Rc224, NSIC Rc226, NSIC Rc238, NSIC Rc272, NSIC Rc278, NSIC Rc280 and NSIC Rc282.
• There was a relationship observed between tungro incidence and yield reduction as shown in Figure 7 and 8.
• Although yield decreases as the incidence of tungro increases, there were, however, varieties that had lower yields (<3.5 t ha-1) even if tungro incidences were zero. Hence, tungro alone may not be the only reason for yield reductions. In fact, some varieties were found resistant to tungro but had low yields.
Figure 1. Profile of injuries due to diseases
Figure 2. Tungro incidence during WS2011
Figure 3. Tungro incidence during DS2012
Figure 4. Tungro incidence during WS2012
Figure 5. Tungro incidence during DS2013
Figure 6. Tungro incidence during WS2013
Figure 7. Relationship between tungro and yield during the wet season
Figure 8. Relationship between tungro and yield during the dry season
Insect Pests
• Insect pests that were observed include stemborers causing deadhearts (DH) and whiteheads (WH); leaffolders (LF); whorl maggot (WM); and defoliators (DEF) that include cutworms, skippers and short-horned grasshoppers.
• Insect pests were present during wet and dry seasons but incidences recorded were minimal in relation to yield loss contribution.
• Presence of rice bug was also observed during flowering to milking stages of the crop. Indirect effect was observed to contribute to the grain discolorations for most early maturing varieties.
Weeds
• Hydrolea zeylanica (HYDZE) ranked first among the major weeds at PhilRice Negros followed by Sphenoclea zeylanica (SPDZE), Paspalum distichum (PASDI), Leptochloa chinensis (LEPCH), Echinochloa species, Monochoria vaginalis
(MOOVA), Fimbristyllis miliacea (FIMMI), Cyperus iria (CYPRI) and Ludwigia octovalvis (LUDOC).
Figure 9. Profile of injuries due to insect pest
Figure 10. Profile of weeds incidence
Recommendations
• Thorough land preparation must be strictly imposed to avoid or lessen problems with weeds. Allowing HYDZE to grow with rice at ratios of 1:1, 1:3, 1:5, 1:7, 1:10 and 1:20 reduced grain yield of rice by 19.6, 24.9, 23.3, 36.2, 40.9 and 56.1
% (DKM Donayre and CA Endino, 2014, unpublished result).
Plowing and or dry land preparation is recommended every after cropping season to destroy stubbles that serve as host for various pests.
• Avoid planting of varieties that are susceptible to tungro. If there’s really a need to plant susceptible varieties for seed purposes, maximum protection must be done at the start of the sowing process.
• Practice synchronous planting.
• Various diseases are observed to occur mostly during the wet season, therefore, right amount of fertilizers and right timing of application must be strictly monitored and implemented.
• Further studies are to be explored for the control and management of Hydrolea zeylanica, Paspalum distichum, Leptochloa chinensis, and tungro.
Literature cited
• Donayre, DKM and CA Endino-Tayson. 2014. Competitive ability of Hydrolea zeylanica (L.) Vahl against transplanted- irrigated lowland rice. (unpublished data)
Monitoring rice productivity in a long-term inorganically fertilized field at PhilRice Negros
DKM Donayre and AOV Capistrano
At PhilRice Negros, the conventional method of producing rice seeds was implemented, which utilizes synthetic fertilizers every season.
Though organic materials were annually incorporated into the soil of the seed production areas, synthetic fertilizers were still the major source of nutrients for fertilizing the rice crops. However, continuous application of inorganic fertilizers may have impacts on productivity as well as sustainability in the long term as it may threaten sustained soil fertility in the future.
A study was conducted at PhilRice Negros to monitor the productivity and sustainability of rice monocropped areas in the long-term to prevent future nutrient imbalances. Specifically, this long-term study aimed to analyze yield trends of inorganically fertilized field and determine nutrient imbalances and changes in fertility that may occur due to prolonged use of inorganic/
synthetic fertilizers. The study that had been implemented since WS 2011 was arranged in RCBD with three replications. Different fertilizer treatments are shown below in Table 1.
Table 1. Experimental treatments
Fertilizer Treatments
N
(kg ha-1) P
(kg ha-1) K
(kg ha-1) Time of N Application (days after transplanting)
0 14 24 42 55-65
DS WS DS/WS DS/WS DS WS DS WS DS WS DS WS DS WS
Control 0 0 0 0 - - - - - - - - - -
PK 0 0 50 35 - - - - - - - - - -
NP 131 105 50 0 38 35 - - 38 35 38 35 17 -
NK 131 105 0 35 38 35 - - 38 35 38 35 17 -
NPK 1 131 105 50 75 38 35 - - 38 35 38 35 17 -
NPK 2 (SSNM) 149 119 30 70 - - 52 26 39 26 39 40 19 26
DS – dry season, WS – wet season
Findings
• Yields of PSB Rc10 and PSB Rc18 varied among cropping seasons (Figure 11).
• Plots supplied with P and K had lower yields compared to plots with no fertilizer (control).
• In terms of effect on grain yields, however, analysis revealed that there were no significant differences between treatments on both rice varieties.
• No interpretation or correlation yet had been drawn relating yield trends with nutrient imbalances and changes in soil fertility due to prolonged use of inorganic/synthetic fertilizers.
Data were still on the process of analysis and interpretation.
PSB Rc18
PSB Rc10
Figure 11. Yield of PSB Rc10 and PSB Rc18 under long term inorganic fertilization at PhilRice Negros.
Effect of rice straw treated with different compost inoculants on soil properties and rice yield
JEAD Bibar
Soil fertility is one of the most important factors in crop production.
Due to intensive cropping over the years, soil fertility in agricultural areas, especially in rainfed areas, has been observed to decline, and together with variability in rainfall, it limits crop productivity. In rainfed rice areas, this soil constraint must be addressed to increase productivity even with variable rainfalls. Improvements in soil and rice productivity can be achieved by supplying the soil with balanced plant nutrients, increasing soil fertility and building soil organic matter. Application of additional organic matter is one of the feasible nutrient management options for rice farmers in order to improve their soils’ conditions.
Rice straw is a potential source of organic matter and soil nutrients in rainfed rice areas. It is the most common farm waste and immediately available for farmers. However, its complete decomposition after soil incorporation is important to minimize harmful effects of decomposition products, such as organic acids, to rice seedlings. Rice straw degradation may be enhanced using inoculants that have been tested and are already commercially-available for farmers at low-cost. This study aimed to determine the effects of inoculated rice straw on the rainfed rice yield and soil properties.
Highlights:
• From WS 2011 to DS 2013, fresh rice straws mixed with compost inoculants were incorporated into lowland soil at 2 t ha-1 at 14 days before transplanting (DBT). Rice crop was grown under full rainfed lowland conditions.
• Soil properties (soil pH, organic matter, available phosphorus and available potassium) were observed to vary in their dynamics every season (Figure 1) but were generally not significantly different among treatments.
• Dynamics of soil chemical properties could have been influenced by the availability of rainfall and the fresh rice straws used.
• During WS 2011 and DS 2012, grain yields of PSB Rc14 ranged only from 1t to 1.5t ha1-, which were due to high incidence of tungro (Figure 12).
• In WS 2012, NSIC Rc272, a newly-released rainfed variety, showed less susceptibility to tungro.
• Grain yields ranged from 3.5t to 4.3t ha1-, but were not significantly different among treatments (Figure 13).
• However, in DS 2013, drastic decline in yield of NSIC Rc272 was due to drought conditions from maximum tillering stage onwards.
Figure 12. Properties of soils with rice straws and compost inoculants at various sampling periods.
Figure 13. Grain yield of lowland rice from plots applied with rice straw (RS) and different compost inoculants
Evaluation of the effects of various organic rice cultures in Negros Island JEAD Bibar
Negros Occidental and Negros Oriental, through its Provincial Ordinance No. 007 (2007), continue to institute and uphold stringent measures toward the protection of biodiversity and the attainment of the status of Negros as an organic food island. In organic farming, a key component is the utilization of locally-produced and low-cost biomass resources to rebuild and maintain soil productivity. Application of organic fertilizers produced from farm biomasses as well as supplemental applications of fermented plant extracts forms part of the organic agriculture system which seeks to promote ecologically sound, socially acceptable, economically viable and technically feasible production of food and fishes (RA 10068 or the Organic Agriculture Act of 2010). Organic farmers are encouraged to prepare their own concoctions or fermented solutions produced from different organic materials by microbiological processes.
These are then applied in their farms as fertilizers and soil amendments.
Organic rice farmers have claimed that after at least 5-7 years of organic farming, rice yields have stabilized and are comparable to yields of conventionally-produced rice. However, information and relevant data are limited for the scientific community to confirm these testimonies. Moreover, organic rice farmers in Negros and their organic farming systems are not well documented. Thus, it is appropriate for PhilRice Negros to identify the various organic rice cultures promoted within the Negros Island and evaluate it through appropriate research conducted inside the station. This study aims
to evaluate the effects of various organic rice cultures on the yield and soil properties of the seed production areas of PhilRice Negros.
Highlights:
• Starting on WS 2011, the organic rice cultures surveyed around Negros Island in DS 2011 were duplicated in PhilRice Negros station. All organic rice systems have similar lowland rice management practices except for sources of nutrients and pesticides. The organic culture systems used as treatments are as follows: (Sagay) 20bags OF/ha + organic foliars; (Canlaon) 60bags OF/ha; (Hinoba-an) 40bags OF/ha + organic foliars;
(Bayawan) 100bags OF/ha + organic foliars; and, (Bago) 40bags OF/ha + organic foliars. The different organic rice practitioners were following the same system of developing their own organic fertilizers and foliars, yet they differ in their raw materials and the rate of application for lowland rice. A plot with chemical fertilizer based on site specific nutrient management was added in the treatments starting on DS2012 for comparison with the organic culture treatments.
• Seasonal organic matter, total nitrogen, available phosphorus and available potassium contents of lowland soils every fallow period starting WS 2011 to WS 2013 are shown in Figure 14. The dynamics of these soil chemical properties were shown to vary among the different organic inputs. Total nitrogen is observed to slightly increase in soils applied with organic inputs from Sagay, Canlaon and Hinoba-an after 3 seasons. On the other hand, organic matter and availability of phosphorus and potassium varied across seasons showing no significant build-up after two years.
• Yields of a traditional variety, Camuros, and PSB Rc10 during WS 2011 and DS 2012, respectively, did not reach more than 3 tons per hectare. These varieties were replaced because of low-yielding capacity and high susceptibility to tungro.
• From WS 2012 to DS 2014, a general yield trend of NSIC Rc120 could be observed in all rice systems (Figure 15).
Among the organic rice systems, highest yields were observed from Bayawan and Bago rice cultures in WS2012 and
DS2013. However, in WS2013 and DS2014, highest yield was observed under organic rice culture from Canlaon.
Table 2. Nutrient content of organic fertilizers used for the study.
Source of Organic
Fertilizer OM (%)
(SA Wildes method) Available P (mg
kg-1) Available K (mg
kg-1) Total N (%)
Sagay 4.0 276 1400 0.70
Canlaon 4.0 483 6400 1.02
Hinoba-an 4.5 380 980 0.82
Bayawan 4.5 512 1620 2.35
Bago 4.5 367 3400 1.00
Figure 14. Seasonal organic matter (OM) content, total nitrogen (N)*, available P and available K of lowland rice soil under different organic rice cultures documented in Negros Island, WS2011 to WS2013.
Figure 15. Seasonal grain yield of lowland rice under different organic rice cultures documented in Negros Island.
Yield performance evaluation of newly-released rice varieties grown on the different soil series in region 6 (A collaborative project of PhilRice, DA RFU VI, Provincial and Local Government Units of Aklan, Antique, Capiz, Guimaras, Iloilo and Negros Occidental)
CA Endino, DKM Donayre, IMG Ciocon, EM Libetario and CA Arroyo Highlights:
WS 2013
• A varietal demonstration in Region 6 was conducted in CY2013 in collaboration with DA-WESVIARC.
• Top performing varieties identified since 2008 to 2012 were PSB Rc18, PSB Rc82, NSIC Rc120, NSIC Rc158, NSIC Rc216, NSIC Rc222, NSIC Rc224, NSIC Rc226, NSIC Rc238 and NSIC Rc240.
• Yield data were presented graphically as shown below.
Figure 16. Yield performance of varieties per province, irrigated condition, WS2013
0.0 1.0 2.0 3.0 4.0 5.0 6.0
PSB Rc82 NSIC Rc240 NSIC Rc238 NSIC Rc216 NSIC Rc224 NSIC Rc120 NSIC Rc158 PSB Rc18 NSIC Rc226 NSIC Rc222 V a r i e t i e s
Negros Occidental, Rainfed
0.0 1.0 2.0 3.0 4.0 5.0 6.0
NSIC Rc158 PSB Rc18 PSB Rc82 NSIC Rc216 NSIC Rc222 NSIC Rc240 NSIC Rc120 NSIC Rc224 NSIC Rc238 NSIC Rc226 V a r i e t i e s Guimaras, Rainfed
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
NSIC Rc120 NSIC Rc158 NSIC Rc240 NSIC Rc224 NSIC Rc216 PSB Rc18 NSIC Rc238 NSIC Rc226 PSB Rc82 NSIC Rc222 V a r i e t i e s Iloilo, Rainfed
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
NSIC Rc158 NSIC Rc120 NSIC Rc238 PSB Rc18 PSB Rc82 NSIC Rc224 NSIC Rc226 NSIC Rc222 NSIC Rc216 NSIC Rc240 V a r i e t i e s Aklan, Rainfed
Figure 17. Yield performance of varieties per province, rainfed condition, WS2013
Abbreviations and acronymns
ABA – Abscicic acid Ac – anther culture AC – amylose content
AESA – Agro-ecosystems Analysis AEW – agricultural extension workers AG – anaerobic germination AIS – Agricultural Information System ANOVA – analysis of variance AON – advance observation nursery AT – agricultural technologist AYT – advanced yield trial BCA – biological control agent BLB – bacterial leaf blight BLS – bacterial leaf streak BPH – brown planthopper Bo - boron
BR – brown rice
BSWM – Bureau of Soils and Water Management
Ca - Calcium
CARP – Comprehensive Agrarian Reform Program
cav – cavan, usually 50 kg CBFM – community-based forestry management
CLSU – Central Luzon State University cm – centimeter
CMS – cystoplasmic male sterile CP – protein content
CRH – carbonized rice hull CTRHC – continuous-type rice hull carbonizer
CT – conventional tillage Cu – copper
DA – Department of Agriculture DA-RFU – Department of Agriculture- Regional Field Units
DAE – days after emergence DAS – days after seeding DAT – days after transplanting DBMS – database management system DDTK – disease diagnostic tool kit DENR – Department of Environment and Natural Resources
DH L– double haploid lines DRR – drought recovery rate DS – dry season
DSA - diversity and stress adaptation DSR – direct seeded rice
DUST – distinctness, uniformity and stability trial
DWSR – direct wet-seeded rice EGS – early generation screening EH – early heading
EMBI – effective microorganism-based inoculant
EPI – early panicle initiation ET – early tillering
FAO – Food and Agriculture Organization Fe – Iron
FFA – free fatty acid
FFP – farmer’s fertilizer practice FFS – farmers’ field school FGD – focus group discussion FI – farmer innovator
FSSP – Food Staples Self-sufficiency Plan g – gram
GAS – golden apple snail GC – gel consistency
GIS – geographic information system GHG – greenhouse gas
GLH – green leafhopper GPS – global positioning system GQ – grain quality
GUI – graphical user interface GWS – genomwide selection GYT – general yield trial h – hour
ha – hectare
HIP - high inorganic phosphate HPL – hybrid parental line I - intermediate
ICIS – International Crop Information System
ICT – information and communication technology
IMO – indigenous microorganism IF – inorganic fertilizer
INGER - International Network for Genetic Evaluation of Rice
IP – insect pest
IPDTK – insect pest diagnostic tool kit IPM – Integrated Pest Management IRRI – International Rice Research Institute IVC – in vitro culture
IVM – in vitro mutagenesis
IWM – integrated weed management JICA – Japan International Cooperation Agency
K – potassium kg – kilogram
KP – knowledge product
KSL – knowledge sharing and learning LCC – leaf color chart
LDIS – low-cost drip irrigation system LeD – leaf drying
LeR – leaf rolling lpa – low phytic acid LGU – local government unit
LSTD – location specific technology development
m – meter
MAS – marker-assisted selection MAT – Multi-Adaption Trial MC – moisture content
MDDST – modified dry direct seeding technique
MET – multi-environment trial MFE – male fertile environment MLM – mixed-effects linear model Mg – magnesium
Mn – Manganese
MDDST – Modified Dry Direct Seeding Technique
MOET – minus one element technique MR – moderately resistant
MRT – Mobile Rice TeknoKlinik MSE – male-sterile environment MT – minimum tillage mtha-¹ - metric ton per hectare MYT – multi-location yield trials N – nitrogen
NAFC – National Agricultural and Fishery Council
NBS – narrow brown spot
NCT – National Cooperative Testing NFA – National Food Authority NGO – non-government organization NE – natural enemies
NIL – near isogenic line NM – Nutrient Manager
NOPT – Nutrient Omission Plot Technique NR – new reagent
NSIC – National Seed Industry Council NSQCS – National Seed Quality Control Services
OF – organic fertilizer OFT – on-farm trial OM – organic matter ON – observational nursery
OPAg – Office of Provincial Agriculturist OpAPA – Open Academy for Philippine Agriculture
P – phosphorus PA – phytic acid
PCR – Polymerase chain reaction PDW – plant dry weight PF – participating farmer PFS – PalayCheck field school
PhilRice – Philippine Rice Research Institute PhilSCAT – Philippine-Sino Center for Agricultural Technology
PHilMech – Philippine Center for Postharvest Development and Mechanization
PCA – principal component analysis
PI – panicle initiation PN – pedigree nursery
PRKB – Pinoy Rice Knowledge Bank PTD – participatory technology development
PYT – preliminary yield trial QTL – quantitative trait loci R - resistant
RBB – rice black bug
RCBD – randomized complete block design RDI – regulated deficit irrigation
RF – rainfed RP – resource person RPM – revolution per minute
RQCS – Rice Quality Classification Software RS4D – Rice Science for Development RSO – rice sufficiency officer RFL – Rainfed lowland RTV – rice tungro virus
RTWG – Rice Technical Working Group S – sulfur
SACLOB – Sealed Storage Enclosure for Rice Seeds
SALT – Sloping Agricultural Land Technology SB – sheath blight
SFR – small farm reservoir SME – small-medium enterprise SMS – short message service SN – source nursery
SSNM – site-specific nutrient management SSR – simple sequence repeat
STK – soil test kit
STR – sequence tandem repeat SV – seedling vigor
t – ton
TCN – testcross nursery
TCP – technical cooperation project TGMS – thermo-sensitive genetic male sterile
TN – testcross nursery TOT – training of trainers TPR – transplanted rice TRV – traditional variety TSS – total soluble solid UEM – ultra-early maturing
UPLB – University of the Philippines Los Baños
VSU – Visayas State University WBPH – white-backed planthopper WEPP – water erosion prediction project WHC – water holding capacity WHO – World Health Organization WS – wet season
WT – weed tolerance YA – yield advantage Zn – zinc
ZT – zero tillage
List of Tables
Page
Table 1. Experimental treatments 9
Table 2. Nutrient content of organic fertilizers used for the
study. 15
List of Figures
Page Figure 1. Profile of injuries due to diseases 4
Figure 2. Tungro incidence during WS2011 4
Figure 3. Tungro incidence during DS2012 5
Figure 4. Tungro incidence during WS2012 5
Figure 5. Tungro incidence during DS2013 5
Figure 6. Tungro incidence during WS2013 6
Figure 7. Relationship between tungro and yield during the
wet season 6
Figure 8. Relationship between tungro and yield during the
dry season 7
Figure 9. Profile of injuries due to insect pest 8
Figure 10. Profile of weeds incidence 8
Figure 11. Yield of PSB Rc10 and PSB Rc18 under long term
inorganic fertilization at PhilRice Negros. 10 Figure 12. Properties of soils with rice straws and compost
inoculants at various sampling periods. 12
Figure 13. Grain yield of lowland rice from plots applied with
rice straw (RS) and different compost inoculants 13 Figure 14. Seasonal organic matter (OM) content, total
nitrogen (N)*, available P and available K of lowland rice soil under different organic rice cultures documented in Negros Island, WS2011 to WS2013.
15
Figure 15. Seasonal grain yield of lowland rice under different
organic rice cultures documented in Negros Island. 16 Figure 16. Yield performance of varieties per province,
irrigated condition, WS2013 17
Figure 17. Yield performance of varieties per province,
rainfed condition, WS2013 17
