Cultivation: The land requirements and cultIvation aspects of popcorn are similar to that of sweet corn. The seed rate is 2.5 kg/ha and the spacing followed for planting is 60 cm x 20 cm or 45 cm x 30 cm. The fertilizer doses recommended are 80 : 60 : 40 kg/ha each of N, P and K. N is applied in three equal splits at sowing, 25 and 45 days after emergence. Zinc Sulphate is to be applied @ 50 kg/ha once in three seasons.

Variety Selection: There are three types of popcorn kernels: white, small yellow and large yellow besides red kernel types. Generally white popcorn has a rice-shaped kernel and yellow popcorn kernels are pearl-shaped. The three kernel types meet different needs within the industry. Growers and processors should consider this when selecting a variety. Industry standards have not been developed for kernel size determination. A common measure is based on the number of kernels in 10 grams. The large one has 52-67 kernels, medium 58-75, and small 76-105.

In India there are principally three released popcorn varieties (Table 1). However, all of them are medium in size and yellow kernel pearl type. These varieties can be grown across the country during kharif season, while in rabi they can predominantly be grown in peninsular India. Besides this another major consideration in popcorn variety selection is maturity because maximum popping potential of a variety can be achieved only if it reaches full maturity. If planting is delayed, consider an earlier maturing variety.

Maturity: Popcorns mature in 85-90 days in rainy season (kharif) and 95¬-100 days in winter season (rabi). Since kernels are the economic product, harvest should necessarily be done on the attainment of physiological maturity, which is evidenced by the formation of a black polyphenol layer at the base of the kernels. For optimum popping expansion the popcorn should be dried to 14-15% grain moisture. The harvested and shelled popcorn is stored in moisture-proof sealed containers.

Cultural Practices: Land preparation for popcorn is similar to that for field corn. The most common method is to use two or three tandem diskings, although some heavy soil types will produce better tilth if ploughed. Disking or field cultivating is then used for seedbed preparation. If needed, a spike-tooth harrow or other finishing tools can be used with the last pass over the field to smooth the seedbed.

Soil Requirements: Any soil type suitable for normal corn, should produce a good popcorn crop. Soil pH should be in the range of 6.0 to 6.8. Popcorn seeds germinate more slowly than dent corn, and the seedlings grow at slower rate. Thus, medium to coarse textured soils, which warm slightly faster than fine-textured soils should improve germination, emergence and seedling establishment. The popcorn root system is less extensive than that of normal corn. Therefore high clay soils and/or poorly drained soils will weaken the roots, reduce yield, and increase lodging.

Fertility: Fertility requirements for popcorn are similar to normal corn. Nitrogen is to be applied at a rate of 100-110 kg/ha. Nitrogen requirements are based on expected yield. In general the rate is 85 percent of the requirement for an expected yield of normal corn in the same field. Any normal corn fertilizer programme adapted to popcorn production should take into consideration popcorn's relatively poor standing ability. However, it must be kept in mind that high nitrogen rates can cause lodging, especially when less than the recommended rate of potash is used. As popcorn seedlings grow slower than normal corn, a starter dose is more important than subsequent split doses. Other nutrients are supplied according to need as shown by soil test, similar to normal corn requirements.

Planting: Kharif popcorn can be planted from the last week of May to the first fortnight of July. A soil temperature of 10-130C is necessary. Planting later than July 15 often results in a reduction of yield and maximum popping expansion. Early planting permits the crop to mature and reach the desired harvesting moisture of 15-18 percent by early to mid-October. Rabi sowing preferably is completed in between October end and middle of November so that the crop can establish itself before the onset of winter.

Seed Rate:Seed rates for popcorn is higher than for normal corn because of its smaller plant size and lower yielding ability. Generally, consider 25 percent increase above the recommended normal corn plant densities for most soils and cultural practices. Row widths of 75-95 cm are common. With irrigation facility the population should be from 50,000 to 67,000 plants per ha. A slightly lower population is used for dry land areas. Thus recommended seed rate for common popcorn varieties in India is 12-14 kg/ha of land.

Irrigation: Irrigation of popcorn is the same as that for field corns. Some growers like to delay early irrigation to stimulate better rooting of the developing plants. However, the value of this practice has not been determined. Irrigation during pollen shed is not recommended. Irrigation, should continue until the black-layer has formed in the developing kernel.

Intercultural operations: Intercultivation with tractor or bullock drawn cultivator is usually undertaken once at knee high stage and if weed situation requires, it is followed by one or two cultivations. Mechanical cultivation will depend upon herbicide effectiveness.

Weed Control: Most effective herbicide for weed control is application of Atrazine or Simazine @ 1 kg ai per hectare. The predominant appli¬cation method is with planting or before emergence. This gives weed protection up to 30-35 days after sowing.

Intercropping: Popcorn being a highly remunerative crop can successfully be cultivated in periurban agriculture. However, instead of cultivating popcorn as sole crop it may be intercropped with other highly remunerative crops like cabbage, cauliflower, radish, spinach, coriander, potato, marigold, garlic, tuberose, gladiolus, spices, pea etc. This provides additional income to the farmers from unit area and makes agriculture more sustainable.

Insect and Disease Control: Most, if not all, of the insects that attack field corn can also attack popcorn. Insect control during the season is important, especially for Stalk borers viz., Chilo partellus Swinhoe in kharif (rainy) season and Sesamia inferens Walker in rabi (post-rainy or winter) season. Spray of Endosulphan @ 2ml/1 within 21 days after sowing is recommended.

Popcorn is more susceptible than field corn to diseases especially stalkrots and ear rots and blue eye disease caused by three types of molds Penicillium viridicatum, P. cyclopium and Aspergillus glaucus. These pathogens not only affect the crop in the field but may affect stored grains leading to low popping volume, low germination and sometimes a low level of toxicity. This disease is best controlled by proper aeration during storage. However, application of Bavistin @ 1 g ai per litre takes care of most of the foliar diseases.

Harvesting: Either ear or shelled popcorn may be harvested. Moisture at harvesting for ear corn should be 18-20%, for shelled corn 16-18%. Harvesting equipment should be adjusted accurately and carefully so that kernel damage is prevented. Damaged kernels do not pop properly and will cause a discount on the grain market. Depending on the proximity of the processing plant, the grain may be delivered directly at harvest or stored on the farm until delivery is requested. If on-farm storage is required, storage facilities must be clean and good aeration must be provided. Aeration is essential for extended storage. Generally, the delivery of the grain is taken at 14-15% moisture, so the storage and aeration facilities must be able to remove some grain moisture.

Relative humidity of 70% will maintain the grain at the proper moisture. Kernels that are too dry will not pop properly. Dirt, cob remnants and other foreign material at harvest must be cleaned before storage. Proper moisture level is the reason to store popcorn properly. For day-to-day use popcorns are to be stored in airtight container and in cool cupboard. Popcorn should not be stored in refrigerator. Air inside a refrigerator contains very little moisture and can cause the popcorn to dry out.

Marketing: Popcorn is mainly produced under contract farming, which specifies the varieties and the acreages to be planted. The grower usually buys the seed through the contracting company. Popcorn seed grown without sales contract is difficult to market and is risky for farmers who do not have appropriate storage facility with good aeration.

Popping Quality: The quality of popcorn is expressed as popped volume, shape of the popped kernels, tenderness, and flavour. Only volume can be measured easily. The popped volume is perhaps most important because the commercial buyers buy on weight basis but sell the popped popcorn by volume. The conventional oil popping methods are still most common. However, air popping and microwave popping are becoming increasingly important in the retail market. Popping expansion of popcorn's varieties varies from 20 to 40:1. Problems associated with low expansion volume, the high number of unpopped kernels and scorching of popped kernels make conventional popping superior to microwave popping. Popcorn variety, the moisture content of the kernels, storage conditions, type of package, and microwave oven wattage influence the quality of microwave popping.

Value Addition: Popcorn while being popped can be coated with salt or sugar or cheese. Sometimes coating with chocolate is also done. This enhances the market value and consumer acceptance. The manufacturers prefer butterfly type of popping due to increased volume since popcorn after popping is sold on a volume basis. However; consumers prefer mushroom types.