EFFECT OF INTERCROPPING SYSTEMS ON FREMONT MANDARIN AND ONION GROWTH, PRODUCTIVITY AND COMPETITIVE RELATIONSHIPS

Field experiments were carried out at private orchard, Wady El-Mollak region, Abo-Hamad district, Sharkia Governorate, Egypt, during the two consecutive seasons of 2022/2023 and 2023/2024 on 7- years old Fremont mandarin (Citrus reticulate Blanco) to evaluate the effect of intercropping systems (1: 1, 1: 2 and 1: 3 of mandarin: onion variety Italian red as row ratio) beside sole planting of each crop as control on the growth, yield components, some chemical constituents and competitive indices between both components. This experiment was set up in a randomized complete blocks design (RCBD) with four treatments in three replicates. Results indicated that, alternating three rows of onion with one row of mandarin trees significantly increased yield components (fruit weight, fruit volume, pulp weight, peel weight, fruit equivalent percentage and total fruit yield per hectare) of Fremont mandarin trees. Intercropping onion plants between mandarin trees at 1: 2 system gained to the highest plant height, more leaves per plant, heaviest fresh weight and largest leaves area average bulb weight of onion. Land equivalent ratio (LER), area × time equivalent ratio (ATER) and land utilization efficiency (LUE) significantly increased with 1: 3 intercropping system compared to the other two ones under study (1: 1 or 1: 2 systems). Mandarin was the dominated component, while onion was the dependent one.