Orchard Management (1+1)

WEED MANAGEMENT IN NEWLY PLANTED TREES

Weed management in newly planted trees

• Newly planted plants in the orchards should always be kept free from weeds as weed competition can reduce their growth and development by 50 percent.
• Newly planted trees suffer from weed competitive more severely than the well established older plantations. Moreover, young tress do not have well-developed limbs to shade the soil surface in late summer to minimize the competitiveness of late summer weeds.
• In general, pre-emergence herbicides provide effective control of annual grasses and small-seeded broadleaf weeds.
• Lower 40-50 cm of the tree trunk should be painted with a white latex paint, which paint provides a barrier to herbicides, and thus protect tender, green bark from burn injury (Plate 6.4).

Plate 6.4: Tree trunks covered with aluminium foil.

Pollination, honey bees, and pesticides.

• Cross pollination (Fig. 6.1) is necessary in apple, some pears, plum, peaches, cherry, pecan nut, kiwifruits etc.
• Most of the apple cultivars grown in India are self-incompatible e.g. Delicious cultivars and require cross-pollinations with a suitable pollinizers’ variety to obtain good fruit set.
• Honey bees and other native insects are the primary pollinators for apples (Plate 6.5).
• All bees are susceptible to insecticides and need to be protected during bloom and at other times.

Figure 6.1.Cross-pollination (a) is necessary for satisfactory fruit set in apples, pecan nut, kiwifruits and some cultivars of pears, plums and sweet cherries. Most peach, nectarine and sour cherry varieties are sufficiently self-fruitful to set full crops with their own pollen (b, c).

Plate 6.5: Honey bee activity during bloom in apple

• Read carefully instructions on insecticide labels: Most insecticide labels include a warming.
• “This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds.
• Don’t apply this product or allow it to drift to blooming crops if bees are visiting the treatment area.
• Any apiary within 21/2 miles of the orchard is at risk from insecticide application.
• Bees are highly attracted to flowers in the ground cover. Before applying insecticides, reduce dandelion, clover, and other ground cover flowers by mowing or herbicide.

• The following recommendations will help to minimize bee kills;

• Read warning statements on pesticide labels regarding honey bees and follow the instructions given.
• Select the safest available formulation. emulsifiable concentrate (EC) formulations usually have shorter residual toxicity than powder (WP) formulations.
• Insecticides applied during unusually low temperatures will remain toxic to bees for a much longer time than when applied in warm weather.
• Avoid applying insecticides to blooming cover crops, and avoid insecticide drift to nearby plants are applied.
• In case the use of an insecticide hazardous to bee must is unavoidable, apply it in the early evening to minimize risk to bees.
• Never apply a pesticide directly over a beehive. Notify nearby beekeepers before applying pesticides toxic to bees.
• Dispose of all unused pesticides safely so that pesticides do not end up in watering sources used by bees.