AGRICULTURAL ENGINEERING
Plate 3. Tomato crop in degraded poly mulch Plate 4. Status of biodegradable polythene mulch after 32 weeks of laying
rose to 34.13, 33.75 and 31.92 % registering an increase by 5.53, 5.38 and 4.88 % respectively, over the initial values.
Polyhouse for production of seedlings
The farmer of Umdohbyrthih village raised the nursery of tomato and brinjal inside the polyhouse.
Seeds of both the crops were sown in first week of April inside the polyhouse. The farmer also placed the seeds in open area on same date on our advice for comparison. The variety sown was Rocky for tomato and RCMB-6 on brinjal. The tomato seedlings grown inside the polyhouse were ready for transplantation in 6th week whereas seedlings grown in open were ready for transplantation in 8th week i.e. almost 10 days later than the seedlings grown inside the polyhouse. On an average 1540 healthy seedlings per m2 of tomato were obtained from the polyhouse whereas from open area 1120 healthy seedlings per m2 were obtained i.e. growing seedlings inside the polyhouse fetched 28% more as compared to the open area. In case of brinjal also same trend was observed.
Seedlings attained transplanting stage in 5th week inside the polyhouse and in 7th week in open condition, almost 12 days later in open condition as compared to the polyhouse condition. About 1610 healthy seedlings per m2 of the brinjal variety were obtained in the polyhouse whereas from open area 1220 healthy seedling per m2 were obtained recording a survival percentage of 24% more inside the polyhoue. Comparatively less temperature and frost might be the reason for slow growth and less survival percentage in open condition.
Protected cultivation
Okra: Arka Abha variety was sown in side the naturally ventilated polyhouse (Fig. 2) in the month
of April. Seeds were sown on raised beds. Before sowing the seeds well-rotten cowdung was mixed in the soil @ 25 t/ha. The spacing between row-to-row was kept as 45 cm and plant-to-plant as 30 cm. Average days of emergence was observed as 4.7. Profused and vigorous growth of plants were observed. Average plant height was 172 cm. No incidence of disease and pests was observed. Therefore, no chemical plant protection measures were adopted. Average fruit length and number of fruit per plant was 18.7 cm and 26, respectively.
Fig 2. Okra crop in the polyhouse
The average yield obtained was 18.7 t/ha. Benefit cost ratio for the current year including the cost of polyhouse was calculated as obtained as 3.1 following the discounting technique.
Tomato: In karif season tomato crop (Fig. 3) was cultivated in the naturally ventilated polyhouse.
Continuous long wet spell during kharif season and high incidence of insects and pests during the period spoil the crops. Tomato is one of the high valued crops in the region and is mainly attacked by wilt and fruit borer. Protected cultivation of tomato eliminated the problems. Tomato seedlings of Rocky variety were panted in the polyhouse in the last week of June. Row- to-row and plant-to-plant distance were kept as 60 and 45 cm. Farm yard manure @ 25 t/ha was incorporated in the soil before transplanting the seedlings. Vigorous growth was observed. Due to profused growth plants were supported with bamboo Fig 1. Sprinkler irrigation system in operation on hill
slope
frame. On an average 33 fruits per plant was obtained.
Per plant yield recorded was 1.130 kg. The yield recorded from 30 m2 area was 123 kg, which is equivalent to 41.0 t/ha. Occurrence of bacterial wilt was observed after 40 days of transplanting. The affected plants were uprooted and burnt out side. To prevent the occurrence of the disease in future, Steptomycine Sulphate @ 200 ppm was applied twice at an interval of 15 days which prevented the occurrence of disease again. The cost of cultivation incurred was Rs. 430 for 30 m2. The cultivation of tomato crop inside the polyhouse gave the B: C ratio of 2.6: 1.
Fig 3. Tomato crop cultivation in polyhouse by a farmer
Strawberry: Entire northeastern hill region experiences high rainfall from May to mid October and intermittent rain during winter season so cultivation of strawberry in open condition is a problem and challenge. A bamboo framed rain shelter was constructed in farmer’s field to study the feasibility of protected cultivation of strawberry.
Polythene sleeves of 9" diameter was used for planting the strawberry seedlings. Well rotten cowdung and soil in ratio of 3:1 and one table spoon of ground cow bone was mixed properly and filled in sleeves. The seedlings were planted in the sleeves in the month of September. When plants were established DAP was applied. Fruiting started in the month of December and was continued upto April. DAP was again applied
@ about 10 g in each sleeves in the month of February.
Irrigation and weeding was done as done as and when required. Rise in the air temperature inside the structure was about 3-40C. About 12 to 15% fruits obtained from open area were damaged either by disease, bird bite, black spot or frost. Vegetative growth of the plants inside the structure was more vigorous. The average number of fruits per plant inside the rain shelter was recorded as 47 whereas in open
areas it was 41. The size of fruit was also bigger in case of rain shelter. The average weight per fruit from the rain shelter was 14.5 g while 11.3 g from the open area. On an average form the entire fruiting period from December to April, about 682 g of fruits per plant were obtained from the rain shelter which is about 47% more as compared to open area. The cost of construction of the rain shelter was Rs 146 per m2 which increased the yield by 1.10 kg per m2. The study showed that rain shelter enhances yield and of strawberry and economically feasible (Fig. 4).
Fig 4. Strawberry crop cultivation in polyhouse by a farmer
Round-the-year-utilization of polyhouse
As vegetable is considered as high valued crops in the entire NEH region, cultivation of vegetables inside the polyhouse may fetch handsome remuneration to the growers by way of round-the- year cultivation of good quality produce. Three cropping sequences viz; tomato-french bean-cabbage, capsicum-tomato-cabbage, and capsicum-tomato- lettuce were tried to ascertain the better one to fetch higher income to the farmer. As per the farmers’
practice only FYM @ 25 t/ha was applied before sowing of each crops. The cost of cultivation was estimated by taking into account the cost of labour, seed, FYM, etc. The market price existing at the time of harvesting of crop was taken into account for estimation of financial benefit. The cost of construction of low-cost polyhouse including cost of bamboo and labour was worked out as Rs 156.40 /m2 of covered area. Two cropping sequences were followed in the polyhouse. They were capsicum- tomato-lettuce and tomato-French bean-cabbage.
Polyhouse was divided into two halves each comprising of 18 m2 area. In one half one sequence was practiced while other half was assigned for other sequence. Total value of produce from capsicum- tomato-lettuce was calculated as Rs. 1964 and Rs.
1368 from tomato-French bean-cabbage. The net annual income for capsicum-tomato-lettuce sequence was worked out as Rs. 109.10 per m2 of land area whereas for tomato-french bean- cabbage sequence net annual return per m2 land area was calculated as Rs. 76.0. Overall Benefit: Cost (B: C) ratio of the production system was calculated by following discounting technique. For the analysis cost of construction of low-cost polyhouse, its annual maintenance cost, and cost of crop cultivation including labour and inputs costs, and net return based on prevailing market price of the produce was considered. The service life of the polyhouse was considered as 5 years with one major repairing in 3rd year. The B: C ratio for capsicum-tomato-lettuce sequence was calculated as 2.1 and 1.7 for tomato- French bean-cabbage.