Smallholder Tree Growing in Philippine Back Yards: Homegarden Characteristics in Different Environmental Settings - Smallholder Tree Growing for Rural Development and Environmental Services - page 51

are also common in the lowlands, but are less frequently in the upland village.
Overlap between the different strata is often limited to a small part in the back of the
homegarden where trees and shrubs form a natural boundary.

2.4.3 Differentiation of Tree and Non-tree Crop Combinations

Six types of tree and non-tree crop combinations can be identified on the basis of a
hierarchical cluster analysis performed with data of all homegardens in this study
(Table 2.4a). For the tree crops, a distinction can be made between the fruit-tree
based mixtures of mango with either papaya or guava as key species (Type 1 and 2)
and the vegetable-tree mixtures with Moringa oleifera (horse raddish) as single key
species (Type 5) or with papaya (Type 4) or the timber tree Gmelina arborea (Type 3)
as second key species.
The joint occurrence of tree- and non-tree crop mixtures within homegarden
fields and the distribution of different types of combinations are shown in Table
2.4b. Only 10.5 percent of all homegardens have solely trees, i.e., thus lack seasonal
vegetables and tuber crops (sum of non-tree crop combination Type 7 in Table
2.4b). Another 22.8 percent is composed of a true mixture of both tree and non-tree
crops (no dominant species; Type 6 x Type 6 in Table 2.4b), whereas about 25.6

Table 2.4 Different types of tree and non-tree crop combinations (a) as identified by hierarchical
cluster analyses, (b) their relative distribution (in percentage) per site and (c) their joint occurrence
(in percentage) for all homegardens at the village study sites in Northeast Luzon, the Philippines
(a) Species Type of crop combination

1 2 3 4 5 6

I Trees:
Moringa oleifera X X V V V X

X
X
X
X
X
X
X

Cocos nucifera X X X X X

Annona squamosa X X

Carica papaya F F X

Citrus grandis X

Mangifera indica F F

Psidium guajava X F X X

Gmelina arborea X X Ti

II Non-trees:
Ananas comosus X X

X
X
X
X
X
X
X
X
X

Musa sp . X X F X X

Abelmoschus esculentus X

Solanum melongena V V V X X

Phaseolus vulgaris X X

Colocasia esculenta Tu X X T X

Ipomoea batatas T X T

Manihot esculenta X

Capsicum frutescens X X X

Zingiber officinale S
F, V, Ti, Tu, S: fruit, vegetable, timber, tuber or spice crop as dominant (key) species, always pres-
ent in indicated mixture
X: species not always present in indicated mixture