21 



An Unusually Good Book 



Hunger Signs in Crops. A symposium written by a group of fifteen spe- 

 cialists in agronomy, horticulture, plant nutrition, and plant diseases. Pub- 

 lished by the American Society of Agronomy and the National Fertilizer 

 Association. Judd and Detweiler, Inc., Washington, D. C. 1941. Pp. 340. $2.50 



Hunger Signs in Crops gives in a very practical manner the 

 symptoms that develop in growing crops when they lack needed 

 mineral elements. The book is timely, for nutritional experts inform 

 us that our diets are woefully lacking in vitamins, proteins and 

 minerals. When plants lack minerals they cannot grow normally, 

 and man and animals that feed upon these plants do not obtain the 

 essential food elements. 



The seventy-nine color plates in the book are well chosen and 

 illustrate clearly the many points emphasized throughout the vol- 

 ume. As an example, the picture of a grapefruit with aborted seed 

 and gum pockets in its axis clearly shows boron deficiency. The 

 normal fruit in section is shown for comparison. In addition to the 

 colored plates there are ninety-five halftones that vividly show the 

 results of mineral deficiencies in the plants. The plants discussed 

 are the ones we deal with in our daily life. The pictures illustrate 

 the poor vegetables and fruits that we often purchase unwittingly 

 from the store. 



The opening chapter deals with general considerations but fol- 

 lows with a discussion of tobacco, corn and small grains, potato, 

 cotton, vegetables or truck crops, deciduous fruit, legumes and citrus 

 fruits. 



The book was designed to be non-technical so as to increase its 

 usefulness. The material was planned for county agents, agricultural 

 teachers, progressive farmers and a source book for libraries and 

 scientists. The clear pictures show at a glance what is wrong with a 

 plant. Thirty minutes spent in the projection of the splendid plates 

 will teach a student more about mineral deficiencies than ten hours 

 of didactic work. Botanists and all lovers of nature cannot afford to 

 ignore this book if they wish to be classified among the well in- 

 formed. 



As one turns the pages of the book one is confronted with the 

 need of the following fertilizers in the soil : nitrogen, potassium, 

 phosphorus, sulfur, magnesium, calcium, iron, manganese, boron, 

 zinc and copper. When these elements are lacking, we have the ready 



