Staggered harvesting of bokchoy (Brassica rapa subsp. chinensis) and lettuce(Lactuca sativa L.) as a simple technique to improve productivity and foodavailability in urban setting

Food insecurity is a serious problem in urban areas and increasing vegetable production and consumption is a strategic action. Many vegetables are one-time harvested which contributes to volatility of food supply and price. This study explored the potential of staggered harvesting in improving yield and extending supply from one cropping. Two common leafy vegetables - bokchoy (Brassica rapa subsp. chinensis) and lettuce (Lactuca sativa L. cv. Lollo Bionda) were grown in plastic bags and subjected to one-time harvesting at 4 weeks after transplanting (WAT) as control and staggered harvesting at weekly or two-week interval starting at 4 WAT up to 8 WAT. Leaf count, area and mass did not significantly differ with treatment during the first 4 weeks of growth. Thereafter, the two staggered harvesting methods markedly increased leaf production in both crops. Weekly harvesting was more promising, increasing yield by more than 2-fold based on leaf count and more than 4-fold based on leaf mass relative to that of one-time harvest. This yield increases more than compensated for the additional 4 weeks of the growing period.