Vegetable gardeners can't win the battle with the weather. The very wet and cool summer is playing havoc with not only the tomatoes, but also all of the vine crops. These include cucumbers, cantaloupe, pumpkins, watermelons, zucchini and other squash.

Many of the vine crops, especially zucchini, have been slow to produce fruit this year. This is because of the poor pollination by bees. All of these crops produce two types of flowers, male and female. Bees must carry the pollen of the male flower to the female flower to produce fruit. Cold, wet weather reduces bee activity.

Gardeners can hand-pollinate by transferring pollen from the male flowers to the female flowers with a small paintbrush. The male flower is on the end of the stalk. The female flower is attached to a swelling that resembles a miniature fruit. Once pollination is complete, the small swelling at the base of the female flower grows into a full-sized fruit.

The cold, wet weather that reduces bee activity can cause poor pollination of cucumbers. This can result in misshapen or tough fruit with large seeds.

Most home gardeners are familiar with blossom end rot, which was prevalent on tomatoes last year. It is occurring on zucchini and watermelon this year. A water-soaked, sunken spot develops on the end opposite the stem of the fruit. The spot enlarges and turns brown or black and may be moldy.

This disorder is caused by the lack of calcium in the developing fruit. The lack of calcium is the result of damaged roots. Factors that cause this damage are extreme fluctuations in soil moisture (either very dry or very wet), rapid early growth followed by extended dry weather, or excessive rain that smothers root hairs. I don't have to tell you which is the problem this summer.

Alternaria leaf spot is a fungus that thrives in wet weather with nights below 60 degrees and can attack all vine crops, especially pumpkins. Dry, corky sports up to ½-inch in diameter appear on the fruit. A sticky substance may ooze from the spots in moist weather and a dark green velvety growth covers the spots. Fruit can rot and decay. White spots appear on the leaves and the dead tissue falls out of these spots. Fruit is attacked at all stages of growth, but young fruit is most susceptible.

The most destructive disease of melons and cucumbers is anthracnose, which occurs in rainy weather when the daytime temperature hovers between 70 and 80 degrees. Yellow, water-soaked spots develop on melon and cucumber leaves, enlarge rapidly and turn brown and dry. The leaves turn black on watermelon leaves. Whole leaves and vines die. Large fruit is spotted with sunken, dark brown circular spots. Pinkish ooze may emerge from the spots. Young fruit darkens, shrivels and dies.

The two fungus diseases, anthracnose and alternaria leaf spot, can be controlled with Daconil 2787. There are no chemical controls for misshapen and tough cucumbers or blossom end rot. However, blossom end rot usually decreases later in the season.

The gloomy weather can also affect the flavor of cantaloupe. This is often attributed to cross-pollination of the melon and cucumber. This is not the case, as the two plants do not cross-pollinate.

Pete Hale of Sarver is a Master Gardener with the Penn State Master Gardener program.