in plots of 3x2 m2 with 45 cmx15cm spacing. The experiment was totally free from attack of any pest and diseases. 50% flowering was observed in VL- 40 on 20th November’07 and VL-42 on 22nd November’07 and average plant height in VL-40 was recorded 137.73 cm and in VL-42 was 143.5 cm. Yield of VL-40 was .34 t/ha and VL-42 recorded .33 t/ha
TUBER CROPS DISEASES
Evaluation of potato tuber varieties against location specific diseases
Seven potato tuber varieties namely, Himalini, Kufri Jyoti, Kufri Giriraj, Kufri Megha, Kufri Sherpa, Kufri Chipsona and SSC-562 were collected from the Agronomist, Potato Seed Farm, Tawang, AP and planted in a plot size of 2.5 x 3.5 m2 in three replications on 31st October’07.
Appearance of late blight was first noticed in Himalini and disease severity was recorded in 0-9 scale in one month interval and final disease observation before harvest showed Himalini, Kufri Giriraj, Kufri Megha and Kufri Sherpa were with highest late blight incidence scoring 9 with all leaves, stems and tubers got infected while Kufri Jyoti showed disease score 6 and Kufri Chipsona and SSC-562 showed tolerant reaction with disease score 3. However it was observed that the disease severity had not much effect on yield and highest yield was recorded on Kufri Giriraj (10.21 t/ha) followed by Kufri Chipsona (7.43 t/ha), Kufri Megha (7.23 t/ha), Himalini (6.91 t/ha), Kufri Sherpa 6.86t/ha), Kufri Jyoti (4.94 t/ha) and lowest in SSC –562 (1.77 t/ha)
Karna Khatta) during May, 2001. Among different combinations of rootstocks and scions, Citrus latipes + Hill Mandarin attained the maximum plant height (2.75 m), root stock diameter (6.9cm) and no. of branches (16). Out of different rootstock - scion combinations, Tanyum + Khasi mandarin produced highest number of fruits (82) after 6th year of planting followed by Tanyum + Hill mandarin.
Further, it is observed that C. latipes + Hill mandarin recorded the highest fruit weight, fruit diameter and juice content. T.S.S. (10.4 0B) was found to be highest in Tanyum + Sikkim orange.
Acidity was higher in Trifoliate + Khasi mandarin (0.75 %) while the lowest was observed in Tanyum + Sikkim orange (0.51%).
Effect of organic manures and inorganic fertilizers on Khasi mandarin
An experiment was laid out with 12 different doses of organic manures comprising FYM, pig manure, poultry manure and four different doses of inorganic fertilizers (NPK). Results indicated that highest number of fruits per plant (663) was recorded with 600, 400, 400 g NPK application followed by 80 kg application each of pig manure and FYM. Plant height (6.96 m) and crop canopy (5.7x5.6 m) were highest with full dose of NPK.
However, stem diameter (86.8 cm) was highest with the application of 80 kg pig manure. Though the number of fruits and fruit yield were low with application of organic fertilizers than the full dose of NPK, the numbers of fruits in extra special and special grades were high with organic nutrient sources. The physico-chemical characteristics of fruits showed that peel weight (32.14 g) and thickness (4.2 mm) were more with full dose application of NPK while segment weight (87.52 g) and fruit weight (120.4 g) were highest with 80 kg FYM followed by 80 kg pig manure.
Development of seeds/fruit (6.63) was lowest with the application of 60 kg poultry manure. Juice content (54.45 ml) and TSS (11.2) was also highest with FYM and Pig manure application.
Performance of Khasi mandarin under high density planting
Data were recorded on fruit quality of Khasi mandarin in its 7th year, planted in HDP with three different spacing of 2 m x 2 m, 2.5 m x 2.5 m and 3 m x 3 m. It was observed that 3m x 3 m spacing
had fruits with highest weight (117.26 g), size (4.9 x 6.1cm2), segment weight (76.28 g) and also juice content (54.6 ml). On the other hand, highest acidity (0.53 %) was recorded in 2m x 2m spacing.
Rejuvenation of Khasi mandarin
A trial was laid out to standardize the top working height in the old Khasi mandarin orchard with the following heights viz., 0.5m, 1.0m, 1.5m, primary branch pruned and control (without pruning). It is noticed that after 7th year of dehorning control (without pruning) produced plants with maximum height (8.3 m), no. of branches (21), canopy spread (4.91 x 4.88 m2) and shoot length (6.0 m). But the highest no. of fruits (418) was obtained in primary branch pruned plants while least no. of fruits (223) was recorded in 0.5m rejuvenated plants. Maximum fruit weight (146.7 g), fruit size (6.5 x 5.2 cm2), segment weight (105.5 g), juice content (76.8 ml) were achieved in plants with primary branch pruned. The highest TSS (10.4°B) and acidity (0.83%) were observed in 1.5m pruned plants.
Performance of micro propagated plants of Khasi mandarin
Micro propagated plants of 10 years old were evaluated for their growth and yield characteristics.
It was observed that the plants are uniform in height and are having similar shape fruits with good keeping quality. Data were recorded in average plant height (3.32 m), stem growth (6.1 cm), number of primary branches (16) besides on number of fruits per tree (537), fruit drop percentage (7%), fruit weight (108.4 g), TSS (11.230 B) and acidity (0.52%).
Maintenance of germplasm
Germplasm block was established and maintained with 14 different varieties of sweet oranges, eight mandarin oranges and 10 different important rootstocks. Root stocks like C.volkumeraina, C.trifoliata and C.jigardio were mass multiplied and maintained.
Performance of Kinnow at low hills of Arunachal Pradesh
Kinnow, a hybrid between King orange and Willow leaf mandarin was evaluated for their performance under mid hills of Arunachal Pradesh.
It was observed that fruits are bright orange in colour, oval, glossy and slightly tight skinned. The fruits recorded an average weight of 135.05 g, fruit size 5.11 cm x 6.85 cm, juice content of 56.80 ml, TSS of 8.84 °B and 1.96% acidity.
GUAVA
Performance of guava varieties under different spacing
Field trial was conducted with two different varieties Allhabad safeda and L-49 under different spacings viz., 3x4 m, 3x3m and 4x4m. It was observed that Allahabad safeda performed better in all the three different spacings. L-49 recorded more number of fruits (571/tree), yield (75 kg/tree)) and fruit weight (174.38 g) under 4x4 m spacing.
AONLA
Performance of aonla varieties
Six different cultivars viz., Assam local, NA-6, NA-7, Kanchan, Chakkaiya and NA-10 were planted in 2000 to evaluated their performance. It was observed that assam local performed better than other improved varieties under mid hill condition. Assam local recorded early fruiting and higher fruit yield (4 kg/tree). Cultivars like chakkaiya and kanchan didn’t give flowering even after eight years of planting.
BANANA
Thirty germplasm of banana have been maintained at the Research Farm. Karpura chakrakeli attained maximum vegetative growth.
While highest bunch weight (6.2 kg), number of hands (14), finger per hand (18) were recorded in Chinni champa followed by Malbhog and Hatidath.
High density planting in banana
Trial was conducted to identify the best planting density for banana varieties. Planting densities viz., 3x2m, 1.8x1.8 m, 1.5x2 m and 1.5 x1.5 m were tried with four varieties viz., Chini champa, Malbhog, Hatidath and Dwarf Cavindish. It was observed that Dwarf Cavindish performed better under 1.5x1.5 m spacing followed by Malbhog.
However, Chinni champa came to flowering well earlier than other varieties with wider spacing
(1.8x1.8m). The bunch weight (7.4 kg) was higher with Dwarf Cavindish without any blemishes.
PEACH
Three low chilling varieties of peach namely Sharbati, TA-170 and Flordasun were evaluated for their yield attributing parameters under mid altitude condition. It was noticed that Sharbati recorded the highest yield of 933 fruits/plant followed by TA- 170 (723).
PERFORMANCE OF INDIGENOUS FRUITS Different indigenous fruits of Arunachal Pradesh were evaluated to study their growth performance. Taktir and Buri fruits are eaten raw by the local people and can also be used for preparation of squash and pickle. It was observed that the species like Tagu guti, Taktir, Saam kothal, Naspati and Takuk performed well under Basar condition. Among different species, Taktir (205 fruits /tree), Hilum (108 fruits /tree) and Buri (74 fruits/tree) performed better and came to fruiting within seven years. Since Taktir has good natural colour, it can be used for preparation of processed products like squashes.
VEGETABLES
Package of practices were developed for sprouting broccoli, spinach, local cabbage, okra for their better performance under mid hill condition of Arunachal Pradesh. Sprouting broccoli was introduced to grow in off-season. It recorded good
TSS (4.0 Bx), pH (6.8), acidity (0.32%), reducing sugars (3.33%) and ascorbic acid (16.2mg/100g).
curd initiation and maturation occurred 54 days and 72 days respectively after maturation.
Performance of Pea var. Azad was evaluated for its growth and yield parameters. It was observed that 50% flowering was recorded after 60 days of sowing while it took another two weeks for pod maturation. The total duration of variety was 120 days with the pod yield of 185g/plant of which seed weight was 92.61 g. chemical attributes recorded were total sugar (3.86%), TSS (4.80Bx), pH (6.1) and acidity (0.26%).
CAULIFLOWER
Effect of boron and molybdenum on cauliflower Field trial was conducted to identify the effect of micronutrients and their mode of application on growth and yield attributes of cauliflower var. Snow crown. It was noticed that combined foliar spray application of borax (0.3%) + ammonium molybdate (0.3%) performed better than soil application. Highest curd diameter (17.43 cm), curd length (14.81 cm), gross weight (225.38 g) and net weight (187.39 g) were recorded with combined foliar application.
TOMATO
Performance of tomato hybrids under polyhouse
Five different varieties of tomato viz., Rocky, Avinash, Cheeranjeevi, Arjuna and PS 225 were grown under polyhouse to evaluate the best variety for off season (Apr-July) production of vegetables.
Among different varieties Arjuna performed well
followed by Avinash and PS 225. Early flowering (55 days), highest fruit set and more yield (3.2 kg/
plant) was recorded with Arjuna. However, var.
Avinash was tolerant to late blight of tomato followed by Arjuna.
AGROFORESTRY
Evaluation of multipurpose trees
During 1997-2001, 53 MPT species have been planted, out of which 49 species are established.
Among 16 tree species established in 1997, Pinus kesia attained maximum basal girth (109.4) and canopy spread (7.86m x 7.92m) after eleven years of planting. Highest plant height was recorded in Michelia obtusifolia (15.91m) followed by Castonopsis indica(15.19m) and Anthocephalus cadamba (15.08m). Chlorophyll content was found maximum in Ixonanthus khasiana (47.5 SPAD) followed by Mesua ferrea (46.6 SPAD) and Livistonia jenkinsiana (46.4 SPAD). Highest light intensity in inter-rows was recorded highest in Terminalia myriocarpa (677.3 lux) followed by Gmelina arborea (556.3 lux) and Anthocephalus cadamba (386.3 lux) and lowest in Mesua ferrea(6.3 lux).
Among the 20 tree species planted in 1998, Acacia mangium attained maximum height (22.33 m) followed by Pinus wallichiana (15.69m) and Penlow (14.88m) and lowest in Morus alba (1.95 m).The canopy spread was found highest in Acacia mangium (9.68m x 8.64m) followed by Pinus wallichiana (7.84m x 7.86m) and Duabanga grandiflora (4.96m x 4.60m) and lowest in Morus alba (1.21m x 1.5m). Chlorophyll content was recorded highest in Symmingtonia populnea (66.5 SPAD) followed by Cunninghamia lanceolata (61.3 SPAD) and Caryota urens (59.1 SPAD) and lowest in Pinus wallichiana (1.5 SPAD). Highest interspacing light intensity was recorded in Gravelia robusta (868 lux) followed by Alnus nepalensis (612 lux) and Lagerstoemia speciosa (551 lux) and lowest in Cunninghamia lanceolata (9.3 lux) followed by Symmingtonia populnea (21 lux) and Cephalo taxus (26 lux).
Among six species established in 1999, Manglietia insignis attained highest plant height
(12.72 m) followed by Parkia roxburghii (12.16 m) and Aleurites montana (11.27m) and lowest in Bauhinia purpurea (4.75 m). The basal girth was found highest in Aleurites montana (70 cm) followed by Manglietia insignis (59.2 cm) and Engelhardtia spicata (59 cm) and lowest in Bauhinia purpurea (23.8). Aleurites montana recorded the highest canopy spread (6.10m x 5.56m) followed by Manglietia insignis (4.78m x 4.92m) and Engelhardtia spicata (4.70m x 4.54m) and lowest in Bauhinia purpurea (2.76m x 2.72m).
The chlorophyll content was recorded highest in Manglietia insignis (44.0 SPAD) followed by Engelhardtia spicata (41.2 SPAD) and Emblica officinalis (27.7 SPAD) and lowest in Aleurites montana (23.55 SPAD). Aleurites montana showed the highest inter spacing light intensity (879 lux) followed by Emblica officinalis (305 lux) and Bauhinia purpurea (264 lux).
Among five species planted in 2000, maximum plant height was recorded in Eleocarpus sphaericus (18.24m) followed by Kobolakso (8.14m) and Sapindus mukorossi (6.7m) and lowest in Aquillaria agallocha (4.97m). The basal girth was found highest in Eleocarpus sphaericus (91.6 cm) followed by Kobolakso (42.8 cm) and Aquillaria agallocha (27.8 cm). Eleocarpus sphaericus also recorded the highest canopy spread (7.51m x 8.2m) followed by Kobolakso (3.94m x 3.88m) and Chukrasia tabularis (1.26m x 1.39m). The chlorophyll content was found highest in Eleocarpus sphaericus (41.7 SPAD) followed by Chukrasia tabularis (36.4 SPAD) and Sapindus mukorossi (34.05 SPAD).
Out of four species planted in 2001, Hiko recorded the highest plant height (7.58m) followed by Litsea lacta (7.10m) The basal girth was found highest in Litsea lacta (41.25cm) followed by Hiko (34.2cm). The canopy spread was recorded highest (3.66m x 3.86m) in Hiko followed by Litsea lacta (3.38m x 3.35m). The chlorophyll content was found highest in Hiko (43.5 SPAD) followed by Lithocarpus sperma (41.5 SPAD). The inter- spacing light intensity was recorded highest in Litsea lacta (131.3 lux) followed by Hiko (67.0 lux).
The soil pH of 50 multipurpose tree species plantations was ranged from 4.3 in Sapindus mukorossi to 3.1 in Kobolakso.
Among 31 combinations of 51 species of MPT and 5 species of cane, Anthocephalus cadamba + Ada was reported best in terms of basal girth (30.5) followed by Alnus nepalensis + Takek (27.33) and Pinus khasiana + Takek (25.33). However, the chlorophyll content was found highest in Alnus nepalensis+Takek (65.03 SPAD) followed by Pinus khasiana+Takek (55.93 SPAD) and Acacia mangium+Taher (53.93 SPAD). The plant height of canes was found highest in Duabanga grandiflora (260.6 cm) followed by Terminalia myriocarpa (225.0 cm) and Castanopsis indica (178.6 cm).
Alnus nepalensis + Takek
Out of different combinations of turmeric and 25 MPT species, highest yield of turmeric was obtained from the combination Duabanga grandiflora + turmeric (9.50 kg / row ) followed by Pinus kesia + turmeric ( 7.60 kg / row ) and Terminalia myriocarpa + turmeric (7.50 kg / row).
Among 12 combinations of MPT species and ginger, the combination Castonopsis indica + ginger recorded the highest ginger yield (4.50 kg / row) followed by Pinus kesia + ginger (3.50 kg / row) and Pinus wallichiana + ginger (2.80 kg/
row).
Among 29 combinations of MPT species and Guinea grass, the combination Castanopsis indica + Guinea recorded the highest guinea grass yield (34.66 kg / row) followed by Chukrasia tabularis + Guinea (30.66 kg / row) and Sapindus mukorossi + Guinea (25.00 kg / row). In all combinations of MPTs and other crops, the length of row was 30 meters.
Morus alba + Guinea grass
Effect of tree densities on the growth performance of Ghamari (Gmelina arborea)
The spacing trial of Ghamari was established in 1999. In 9th year of establishment, Ghamari obtained highest plant height (9.4 m) in the spacing 4m x 4m followed by the height (9.2m) in spacing 6m x 4m. The basal girth was recorded highest (91.2 cm) in the spacing 4m x 4m followed by the girth 90.2 cm in 6m x 4m. The girth at breast height was found highest (67.2 cm) in the spacing 4m x 4m followed by 64.6cm in 6m x 4m spacing.
Spacing trial of Bola (Morus laevigata)
The spacing trial of Bola was established in 1998. After 10 years, maximum plant height (7.95 m) was attained in the spacing 3m x3m followed by 7.20 m in 4m x 3m spacing. The spacing 3m x 3m recorded the highest basal girth (45 cm) followed by 38.4 cm in the spacing 4m x 3m. The girth at breast height was also found highest (33.0 cm) in the spacing (3m x 3m) followed by 28.2 cm in the spacing 2m x 3m.
Spacing trial of bamboo species
Out of 13 species of bamboo grown under three spacing, maximum clump circumference was recorded in Bambusa cacharensis (12.6 m) at 5m x 5m spacing followed by the same species (10.2 m) planted at spacing 6m x 6m. But in spacing 7m x7m, Bambusa nutans recorded the highest clump circumference (8.2 m). Highest number of culms per clump was recorded in Bambusa pallida (47) at 7m x 7m spacing followed by Dendrocalamus sahnii (42) at 6m x 6m spacing and Dendrocalamus hamiltonii (39) at 5m x 5m spacing.