Tropical and subtropical vegetables (2+1)

Preparation of field

• The soil is brought to fine tilth by repeated ploughing and harrowing. Tillage consists of breaking up the hard, compact soil to certain depth by tillage operations like ploughing, hand digging to bring the soil to pulverized mass known as tilth. Twenty five tonnes of FYM/ha can be incorporated into the soil.

Spacing and transplanting
Seedlings are transplanted 4-6 weeks after sowing. Chilli planting at a closer spacing gives higher yield and a spacing of 20X20cm gave higher yields in Uttar Pradesh. A closer spacing of 30X30 cm was found good in Tamil Nadu. In Karnataka 75 X 45 cm distance between rows and plants is being practiced to get higher yields. Bell pepper plant population appears to be the most important single factor for getting higher yields. Maximum fruit yields are got at a spacing of 45 X 45cm. A spacing of 60X30 with 55,000 plants/ha gave highest yields of 12.3t/ha in capsicum cv. California Wonder. In Karnataka 60 X 45cm spacing is recommended for higher yields.

Nutrition
Chilli and capsicum respond well to application of fertilizers both under irrigation and rainfed condition. The nutrient requirements are mentioned below.
Chilli			Capsicum
Nutrients	Irrigated (kg/ha)	Rainfed (kg/ha)	Irrigated (kg/ha)
N	175	100	150
P	75	50	75
K	75	50	50
Good fertile soils with humus are most desirable for growing capsicum. Heavy application of N fertilizers may increase vegetative growth and delay maturity. For rainfed crop 50% of Nitrogen and full dose of P & K applied as basal dose and remaining 50% should be applied 4 weeks after transplanting. While under irrigation nitrogen should be split into three split equal doses and applied at an interval of three weeks. Nitrate form of nitrogen is preferred by capsicum hence it is suggested that for bell pepper nitrate should be supplied at least at double the rate of ammonical nit rogen.
During cooler seasons higher ratios of ammonia to nitrate and in summer almost equal ratio of these two forms was found to favour capsicum production. Pepper plants grown under nutrient film techniques (NFT) and exposed to solar radiation preferred NO3 as the source of nitrogen while imposing shade made the plants to perform well with ammonical and nitrate forms 1:4 ratio. Capsicums were found to respond to inoculation with VAM fungus Glomus irraradices. Azospirillum as a seed treatment and soil application increased vegetative growth in capsicums.

Irrigation
Since chilli is largely cultivated as a rainfed crop, the crop suffers during its various growth phases by moisture stress due to drought spell. Soil moisture stress affects the plant growth and production of chilles. Decreased nitrogen utilization and decreased yield were observed at lower irrigation regions. Phosphorus uptake was severely affected by soil water stress. Moisture stress also resulted in severe flower drop in chilli. The soils with available water holding capacity of 100 to 160 mm per metre depth of soil are ideal for cultivation of chillies.
The crop raised in kharif season is mainly for ripe red chilli purpose. In semi arid regions of the tropics, it is observed that providing supplemental irrigation whenever dry spell exceeds 8 to10 days period almost doubles the chilli yields on red loam soils. Irrigation requirement depends on season of cultivars and soil type. Capsicums are mostly grown during rainy and winter seasons although as it not common to see them being cultivated during summer season. Even during monsoon season whenever dry spell exceeds 7-8 days providing supplemental irrigations are necessary. When the capsicums are grown as irrigated crops, normally furrow method of irrigation is followed.

Weed control
Weed intensity is generally more in red soils than in black soils in the same locality. Weed intensity is high when the crop is grown during kharif season than in Rabi or summer months. Though cultural methods of weed control is widely followed, with the increase in labour wage and scarcity of laborers and some times increased rains preventing these operations, using herbicides or combination of both herbicide and cultural operations are becoming more popular.
A large number of herbicides have been tried, both for transplanted and direct sown chilli crop. Among the herbicides tried, dephenamide, trifluralin, EPTC, Nitrofen had given good results in chilli crop. Various mulches such as saw dust, gravels, crop residues, plastic films etc are used to control weed population.