Top It Off

Top It Off

Advertisement

Tree response to hedging and topping depends on several factors, including variety, tree age, vigor, growing conditions, and production practices. No one system or set of rules is adequate for the numerous situations encountered in the field. Growers are encouraged to gain a clear understanding of the principles involved in hedging and topping, to take advantage of research results, and to consult knowledgeable colleagues and custom operators for their observations.

Make Accurate Cuts

Hedging should be started before canopy crowding becomes a problem that would cause cutting of small branches. Removal of a significant portion of the tree will result in excessive vegetative growth and a drastic reduction in subsequent yield. Hedging is usually done at an angle, with the boom tilted inward toward the treetops so that the hedged row middles are wider at the top than at the bottom. This angled hedging allows more light to reach the lower skirts of the tree. Hedging angles most commonly used are 10 degrees to 15 degrees from vertical.

Topping should be done before trees have become excessively tall and should be an integral part of a tree-size maintenance program. Long intervals between toppings increases the cost of the operation due to heavy cutting and more brush disposal. Topping trees will increase fruit quality and size. Some common topping heights are 12 feet to 14 feet at the shoulder, and 15 feet to 16 feet at the peak.

Easy On The N

Top Articles
Have a Plan For Climate Change? Why Fruit Growers Need To Act Now

Excessive nitrogen after severe hedging or topping will produce vigorous vegetative growth at the expense of fruit production. Therefore, nitrogen applications should be adjusted to the severity of hedging and/or topping. Reducing nitrogen applications avoids an imbalance when heavy pruning is done. Reducing or omitting a nitrogen application before and possibly after heavy hedging will reduce both costs and excessive vegetative growth.

Large crops tend to deplete carbohydrates, which results in a reduced crop and increased vegetative growth the following year. Pruning after a heavy crop additionally stimulates vegetative growth and reduces fruit yield the following year. Pruning after a light crop and before an expected heavy crop is recommended because it can help reduce alternate bearing, which can be a significant problem in Valencia production.

Timing Is Crucial

The best time of year to hedge and/or top depends on variety, location, severity of pruning, and availability of equipment. Since pruning is usually done after removal of the crop, early maturing varieties are generally hedged before later-maturing varieties. Many prefer to hedge early before bloom, but they may also get more vegetative regrowth, which may not be desirable. In cases where excessive growth is to be removed, the trees are usually harvested before hedging is conducted.

Light maintenance pruning can be done throughout the summer and until early fall with little or no loss in fruit production. Moderate pruning should not continue late into the fall in freeze-prone areas, as trees with tender regrowth are more susceptible to cold injury. With the finding of citrus greening disease, selecting the best time for hedging and topping is becoming more complicated. New growth flushes promoted by hedging and topping in late spring, during the summer, and early fall can increase the population of psyllids and aggravate the spread of citrus greening.

0