MANHATAN, Kan. -- Garden fruit crops can develop quality- and quantity-cutting diseases just as the plants break winter dormancy. Or, as they experience rapid growth in early spring.

"Close monitoring and good management are essential to having any hopes for a good harvest. Sometimes, they can affect whether the plant itself is able to survive," said Ned Tisserat, plant pathologist at Kansas State University.

He warned that the most susceptible plants in Kansas tend to be peaches, apples, raspberries, blackberries and grapes.

The dormant oil sprays used to control insects aren’t effective in fighting off the fungus that causes peach leaf curl. To prevent this leaf-damaging disease, apply a fungicide such as chlorothalonil or a copper-based product before peach buds begin to swell -- which can occur as early as late February or early March.

To control fruit-rots, as well, (1) pick off and rake up the old peach pits that harbor these diseases; (2) prune yearly, cutting out only relatively small branches and leaving no large open wounds or branch stubs; (3) monitor to see whether a fungicide’s needed during bloom and before harvest.

"I usually recommend waiting as long as possible to prune peaches -- even up to bloom time," Tisserat said.

Before the trees break dormancy, apply Bordeaux mixture or another copper-based fungicide, to reduce the odds for fireblight disease.

"Be sure to read the fungicide label’s precautions about mixing it with the dormant oils you use to control scale insects," Tisserat advised.

Then, before bud break, take action to suppress both foliar and fruit diseases:

* Remove any fruit left hanging on the tree or lying on the ground below.

* Remove dead and weak limbs.

* Prune out overlapping twigs and branches with poor crotch angles.

* Inspect bark for signs of sunscald, insect borer injury and/or canker diseases.

* Start planning early-season control of scab, rust and powdery mildew.

"From mid-April to late May is a critical time for preventing those diseases," the plant pathologist said. "Susceptible apples will need a protective fungicide applied at seven- to 14-day intervals, starting when the flowers begin to appear and continuing until after bloom."

For some apple cultivars, fruit spray mixes with captan or copper can do a good job. For Jonathans and other apples highly susceptible to rust, however, myclobutanil (sold as Immunox) is the better choice.

"Organic gardeners can substitute wettable sulfur," Tisserat noted. "But it may not completely control all spring apple diseases, particularly rust."

He suggested homeowners drop by their county’s K-State Research and Extension office to pick a copy of the publication "Home Fruit Pest Control." It contains more details about apple trees’ spring and summer disease controls.

Prune out dead or damaged canes. With raspberries, also apply a delayed/dormant application of liquid lime sulfur, to control cane diseases.

"If you’re buying new plants, be sure to check the roots for any galls or swellings. They can be an indication of crown gall," Tisserat said.

Prune the vines. Make a dormant application of liquid lime sulfur. Then, as new shoots begin to emerge, start routine applications to suppress black rot -- a major early-season disease threat for most grape varieties grown in Kansas.

"Be sure to read labels carefully before selecting a black rot preventative," Tisserat said. "Copper products, in particular, can cause injury on some cultivars."

Effective black rot controls include triadimefon (sold as Green Light Fung-Away and others), myclobutanil, captan and copper-based fungicides.