Efeito de diferentes fotoperíodos no crescimento de dois cultivares de alho (allium sativum l.)

Abstract

This experiment was made with two varietics of garlic, the Amarante and Centenario, under greenhouse co􀁦 ditions, to verify the effect of photoperiods of 9, 12 and 15 hours and natural sunlight on the growth of this vegeta­ble. Plants exposed to photoperiods of 12 and 15 hours rcccivcd 9 hours of natural light and incandescent li ght at .:iproximatcly 180 lux for the remaining hours. Results showed that the longer the photope -riod the lowcr the following dry wei􀃁hts in both types of garlic: thc total, thc cxposed parts, sheathes, leaves and roots, and thc longer the photoperiod, the lower the total numbcr of leavcs an<l lcaf surfaces in the two types of gaE lic. In the Amarante variety, the highest rates of growth occurred earlier when the photoperiod was longer. ln both varictics of garlic, the variations in photoperiods affec­ted thc growth of thc bulb much more than they did the expQ sed parts showing that long photoperiods hastened the decre􀀐 SC! of thc bulbar ratio, and thal the longer the photoperiod, the faster thc dcvclopmcnt of the claves. Plants of the Ce!! tcnario variety which wcre exposed to a photoperiod of 9 hours, showed a high r;ite of bulb rotting.