*Section B3: Effects of alley intercropping on the growth and yield of oil palm.*

Oil palm alleys of ages 2, 3, 4 and 6 years were planted with cassava, maize and pepper in intercropping system. By this time, the oil palm plants had not completely closed canopy but expected to create competition in both above-ground and belowground for alley crops. The alley intercrop species affected growth attributes of oil

**Figure 10.** *Effect of age of palm on relative yields of species in the intercropping system.*

*Oil Palm-Based Cropping Systems of the Humid Tropics: Addressing Production… DOI: http://dx.doi.org/10.5772/intechopen.98257*

**Figure 11.** *Effect of age of palm on aggressivity of the intercrop species.*


**Table 8.**

*Effects of alley intercropping (cassava, maize and pepper) on the growth and yield of oil palm.*

palm (**Table 8**). The growth and development of oil palm especially, canopy formation during the early years of establishment (1 to 6 years) appeared to favor sowing arable crops (such as cassava, maize and pepper) in its alleys. The alley crop species (maize, cassava and pepper) exerted no significant detrimental effects on the measured characters of oil palm (including number of leaves, canopy extent, number of fresh fruits bunch (FFB) and weigh of fresh fruits bunch (FFB) (**Table 8**). Oil palm canopy spread increased as the age of the oil palm increased, canopy extent was largest for 5 and 6 years old palm trees compared with the 2, 3 and 4 years. The number of FFB in young palms were more and small in size and lower in weight while the number of FFB in older palms were few and bigger in size. The number and weight of fresh fruit bunch (FFB) were different between the 4 years old and 5 and 6 years old palm trees. The number of fruits per palm ranged from 10 to 16, 8–16, and 10–15 and yields of FFB were on the average, 8.98, 9.28 and 31.93 kg.m2 for the respective 4, 5 and 6 years old oil palm trees (**Table 8**). The number and weights of fruits were in line with NIFOR record on oil palm production [2]. The yields of FFB from 4 to 6 years old palm trees were close to NIFOR standard. The tested plant species grown in mixtures had enhanced productivity over their respective sole crops possibly by exploiting species complementarities for resource capture. The complementarity could have resulted in part from competition avoidance responses for resource capture and use for growth of the individual species [10, 13]. Individual species responses in the mixture (e.g. shade avoidance) and hence differences in resource acquisition in time and space improved the performance of the intercrop community as a whole [23, 35].
